Polar Aligning

I use star drift polar aligning method.

This method can be manually done looking through an eyepiece, but I do it helped by the software EQAlign (freeware).
This software measures the drift velocity of a star in the image on the screen indicating how much should the image of the star be moved to adjust the mount in azimuth and altitude to correct the misalignment.

This minimizes the number of adjustment iterations so in less than an hour you can get a precise alignment with star drift lower than 1 arc second per hour.

Monitor calibration

Monitor calibration
Adjust your monitor to see all grey boxes